Studies of molecular structure and dynamics in heme proteins will be carried out using laser-excited resonance Raman spectroscopy. A theoretical and computational framework for extracting structural information from the spectra will be implemented using recently developed porphyrin force fields and molecular graphics. Protein-heme interactions in cytochrome c peroxidase will be investigated systematically with site- directed mutants. The dynamics of quaternary structure change in hemoglobin will be explored wit ultraviolet resonance Raman spectroscopy. Electron transfer and conformational coupling in cytochrome oxidase will be investigated with transient absorption and Raman techniques. These studies are expected to help uncover the molecular mechanisms whereby oxygen metabolism is linked to biological function through the motions of proteins.